Kaido’s not a counterpart to Ace though, he’s one to Whitebeard. Marineford and Wano are counterparts to each other because both represent a total change of the status quo both in-series and out- the World’s Strongest, an Emperor, former Rocks Pirate, being defeated by a D. Marineford brought about the time skip, Wano will bring around Luffy being a Great Pirate and the series being at the beginning of the end.
I think the most that can be compared between Ace and Kaido is that their deaths might be similarity bittersweet, where Luffy achieving his goal doesn’t make him the outright winner. Luffy did save Ace to a great extent, physically and spiritually. By freeing him from the execution platform he allowed Ace to die of his own volition. There’s a great deal of difference between an execution and a sacrifice for another. It allowed Ace to make a choice, and die as a free man- for the brother he chose, not the father he never knew and was being executed for- and we know how important freedom is in One Piece. And he gave Ace to the answer of the question he was looking for all his life- it was a good thing that he had been born.
The death of Kaido might similarly not be a total success. It won’t bring back Oden, Toki and Yasu, for one thing. If Kaido does kill someone (like Kin’emon), Luffy will have lost while winning, much like he did at Marineford. Oda did say that there would be a cost to victory here, after all.